%0 Journal Article %A A. A. Borisenko %T On extremal properties of compact parabolic surfaces in a Riemannian space %J Sbornik. Mathematics %D 1988 %P 113-127 %V 61 %N 1 %U http://geodesic.mathdoc.fr/item/SM_1988_61_1_a7/ %G en %F SM_1988_61_1_a7